package com.xmg.dataStructure.stack;

import java.util.Scanner;

public class ArrayStackDemo {
    public static void main(String[] args) {
        ArrayStack stack = new ArrayStack(10);
//        stack.push(1);
//        stack.list();
        String key = "";
        boolean loop = true;
        Scanner scanner = new Scanner(System.in);

        while (loop){
            System.out.println("show:显示栈");
            System.out.println("exit:退出程序");
            System.out.println("push:入栈");
            System.out.println("pop:出栈");
            System.out.println("请选择：");
            key = scanner.next();
            switch (key){
                case "show":
                    stack.list();
                    break;
                case "push":
                    System.out.println("请输入一个数：");
                    int value = scanner.nextInt();
                    stack.push(value);
                    break;
                case "pop":
                    try {
                        int res = stack.pop();
                        System.out.printf("出栈的数据是%d\n",res);
                    }catch (Exception e){
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop =false;
                default:
                    break;
            }
        }
        System.out.println("程序退出");
    }
}

class ArrayStack{
    private int maxSize; //栈的大小
    private int[] stack; //数组，模拟栈
    private int top =-1; //栈顶，初始化为-1

    public ArrayStack(int maxSize) {
        this.maxSize = maxSize;
        stack = new int[maxSize];
    }

    //栈满
    public boolean isFull(){
        return top == maxSize -1;
    }

    //栈空
    public boolean isEmpty(){
        return  top == -1;
    }

    public void push(int value){
        if(isFull()){
            return;
        }
        top++;
        stack[top] = value;
    }

    public int pop(){
        if (isEmpty()){
            throw new RuntimeException("栈空，没有数据");
        }
        int value = stack[top];
        top--;
        return value;
    }

    //遍历栈 从栈顶显示数据
    public void list(){
        if(isEmpty()){
            return;
        }
        for (int i = top; i >=0 ; i--) {
            System.out.printf("stack[%d] = %d \n",i,stack[i]);
        }
    }
}


